1. Field of the Invention
The invention pertains to a cold forming by cold rolling process for the production of flat metal ribbon cables.
2. Description of the Related Art
Flat metal ribbon cables, especially of copper or copper alloys, are preferred today as electrical conductors in, for example, the motor vehicle industry, because these flat ribbon cables offer the advantage of better custom manufacturing. Because of their larger surface areas, heat can be also be dissipated more effectively from their surfaces, which means that they can also be subjected to greater electrical loads than a round wire can.
In the production of this type of flat ribbon cable by cold forming with rolls, a round wire is used as the blank, which is usually passed through a multi-stand section of shaped rolls, usually with 4 or more pairs of rolls, to flatten the wire to its final thickness. It is typical in this case that, after every pass, i.e., each time the wire passes through a pair of rolls, the material then passes through another pair of rolls to work the edges, the axes of rotation of this additional pair being perpendicular to those of first pair. This second pass usually occurs in a “closed” manner; that is, the edges of the wire are gripped by a grooved roll. It is also sometimes done simply in an “open” manner, for which a pair of cylindrical rolls is used. It both cases, the dimensions of the blank are adjusted appropriately so that it can be subjected to further processing.
After it has passed through the shaped roll section, the flat ribbon cable is then wound up on a spool or the like and is then available for final processing.
The shaped roll sections in question are mechanical installations which are complicated in design and require sophisticated engineering. They are therefore quite expensive.